1. Field of the Invention
The present invention relates to a light emitting panel and a light emitting apparatus having the light emitting panel, and more particularly to a light emitting panel having reduced cross talk and a light emitting apparatus having the light emitting panel.
2. Description of the Related Art
Recently, a cathode ray tube (CRT) display device and a liquid crystal display device are widely used as display devices. The cathode ray tube has a heavy weight and a large size. The liquid crystal display device has a low luminance, a low light using efficiency and a narrow viewing angle. Thus, both of the cathode ray tube and the liquid crystal display devices are not satisfactory.
One of next display devices is a light emitting apparatus. The light emitting apparatus (or electro-luminescent display apparatus) has a high light efficiency, a thin thickness and a light weight. The light emitting apparatus includes an inorganic light emitting display device and an organic light emitting device.
The organic light-emitting device displays an image by electroluminescence of a specific organic matter (or a polymer), so that the organic light-emitting apparatus needs no back light assembly. Therefore, the organic light-emitting apparatus has a thin in thickness, a wide viewing angle and a high luminance.
FIG. 1 is an equivalent circuit diagram of a general organic light-emitting panel.
Referring to FIG. 1, a general organic light-emitting panel includes a switching transistor QS, a storage capacitor CST, a driver transistor QD and an organic liqht-emtting device OLED. A voltage applying line VDD is elongated in parallel with a data line. A plurality of pixels is electrically connected to the voltage applying line VDD. The number of pixels is equal to the number of the gate lines.
A luminance of the organic light-emitting apparatus is low in comparison with the cathode ray tube display device.
According to a method of driving, the organic light emitting apparatus classified into both active and passive matrix types.
A passive matrix organic light-emitting device is easily manufactured, and its driving method is very simple. However, the passive matrix organic light-emitting device consumes much power. Furthermore, an increasing in scan lines leads to complexity in the passive matrix driving method.
Therefore, an active matrix organic light-emitting device (AMOLED) is widely used. An amount of light emitted from an activation layer of the light-emitting cell is substantially proportional to a density of a current applied to the activation layer.
When an organic light-emitting panel is operated, a cross talk occurs along the voltage applying line VDD.
FIG. 2 is a schematic view showing a cross talk occurring on a general organic light-emitting panel.
The organic light-emitting panel of FIG. 2 corresponds to the organic light-emitting panel having the voltage applying line VDD in parallel with the data line.
Referring to FIG. 2, a column ‘A’ is a region corresponding to a dark color (or gray color). A column ‘B’ is a region corresponding to bright region (or white color).
An amount of a voltage drop of the column ‘A’ is small, but an amount of a voltage drop of the column ‘B’ is large due to the bright region R2. Therefore, a region R3 above (or below) the bright region R2 becomes darker than the region R1, although the region R3 is intended to have the same brightness as in the region R1.
As described above, pixels disposed near the white pixels are influenced by the white pixels. Therefore, as an area corresponding to white color increases, the luminance of the organic light-emitting panel decreases. Further, the brightness of the image is distorted along the voltage applying lines.